I have both Ut and Ut 2003. Ut 2003 is very pretty but it needs too much speed, I have a 1 ghz/geforce 4 card and I have to cut back on some of the visual goodies, so it can run smoothly. Still hiccups but not too often. Even with some of the eye candy turned off, you still can see some nice stuff like caustics(reflections from water). When I get a new machine, it should run much better. If you have a video card that supports pixel/vertex shaders, you should see some cool stuff. Download the demo and try it out. One arena has grass, you don't see it in the demo.